Art of painting porous surfaces.



nurr ens nrnnr orrcn aornn'r s. PERRY, or cavn srnine, crnonem.

ART. 015 PAINTING- IBOZROUS SURFACES.

To all whom it may concern;

Be it known that 1, ROBERT S. PERRY, of Cave Spring, in. the county of Floyd and State of Georgia, have invented a new and useful Improvement in the Art of Paint- .ing Porous Surfaces, whereof the following is a specification.

In using the term porous as indicative of the surfaces to the painting of which my invention is addressed, I mean surfaces having porosity of the character manifested by wood, textile fabric, plaster, concrete, inortar, unglazed brick and unglazed tile, as typical instances, it being noted that in all of these the inherent porosity of the material is of such a character as to manifest it self in capillary attraction for a liquid, such as water.

As the art has heretofore been practised, it is usual, in painting surfaces of this character for protective or decorative purposes,

that the coating may reasonably conform.

cal, such as, resistance to' weather, capacity to shed moisture, and the like, while others are mainly decorative.

The desiderata of a priming coat or coats may generally be stated as follows:

First, sealing quality, or substantial imperviousness to moisture, air, or other forms of liquid or gas.

Second, elasticity or ductility, in order to the conditions of expansion or contraction of the surface.

Third, adhesive quality, including the ability to penetrate the cellular surface, and thus minimize the tendency of the priming to peal 0E therefrom.

Fourth, opaqueness, or substantial concealment of the surface, in order to permit the desired decorative or artistic efiects of the final coats.

Specification of Letters Patent Patentgqil S aph 1L1, 1191?, Application filed January 20, 1917. Serial No. 143,486.

Fifth, substantial freedom from internal strains which would tend to shorten the life of the entire system of coating.

Sixth, uniformity throughout the body of the priming.

Seventh, advantageous surface conditions for the finishing coat or coats, in that the surface to which they are to be applied shall more penetrable and to diminish in sealing quality with age.

Second, while they may have considerable elasticity or ductility when first applied, these qualities progressively diminish with age, and may even ultimately disappear.

Third, while their initial penetration and adhesive qualities are manifest when first applied, they almost invariably contain organic compounds which tend to deteriorate, and hence the danger of peeling 0r chalkin increases ourth, while they may possess opaqueness toa certain degree, yet by reason of the small quantity of pigment, which they usually carry, this is somewhat impaired by the nature of the vehicle, which is usually translucent or nearly so.

Fifth, while they may, when first applied, be substantially free from internal strains, such strains progressively manifest themselves with age, and produce cracks or checking.

Sixth, the formulae for their composition are complex and the material is applied by human agency, so that the personal element enters largely into their application, both as rglargs economy of material and uniformity o o y.

Seventh, their surface condition, considered with reference to the application of the finishing coat or coats, varies with varying conditions of the surface upon which they have been applied, and thus tends to lack of uniformityas a preliminary surface or es pv I have discovered that an initial coating (which may be termed by analogy, a priming) of peculiar character can be appliedto surfaces of the general classmentioned, under conditions "which give it a specific value and novel character both as a priming, per 86, and also for the superimposition of the finishing coat or coats, the total result being that while the latter may be applied in "the structure of the material to'a sufiicient degree to engage physically in the pores thereof; it adheres thereto with great firmness; its coherence is such that it may be considered as substantially continuous; its

uniformity and physical dimensions are readily controllable; and it presents an external surface which is mat, or uniformly dull, owing to the existence of very minute but uniformly distributed interstitial cavities. Although the lead surface thus formed may not properly be termed porous, in a strict sense, and although its cavities are not necessarily related in position or extent to the pores of the underlying. material, yet they afi'ord results which may be said to be comparable to those of a slightly porous surface, in that they afford an almost ideal ground for the finishing coat or coats.

I have found that by the use of the primary coating characteristic of m invention, all the seven qualities above re erred to as desirable, are secured to an extent to which no primings, known to the painters art as heretofore ractised, have attained.

Incidenta ly. there are economic features, such as the reduction of the labor of applivcation, and also the avoidance of waste,

lead priming film, having the characteristics above set forth. v

I have used the term lead, as indicating the material which I. employ, without, how-.

ever, intending to restrict my invention to pure metallic lead as such, but although the presence of other metallic ingredients may be tolerated, the metallic coating shouldcom riseasubstantial percentage of lead.

aving thus described my invention, I desire to state that I do not claim the process of applying hot sprayed metal to a surface, whether porous or otherwise, nor do I claim the application of a coat or coats of paint upon a metallic surface. My invention resides in the'discovery that a film composed substantially of lead and applied to a porous surface in the manner set forth, cooperates in a peculiar and novel manner, for priming purposes, both with said surface and also with the superimposed finishing layer or layers, and consequently enhances the aggregate value of the paint system thus built up. Y

I claim: I As an improvement in the art of painting surfaces of porous material, the hereinbefore described process, which consists in first hot spraying the surface with finely divided lead, to form a .penetrant, adhesive, and coherent film, with a mat external surface; and subsequently applying upon the external surface of the film a coating of vehiclecarried pigment, substantially as set forth. In testimony whereof, I have hereunto signed my name at New York city, in the county and State of New York, this 17th day of January, 1917.

ROBERT S. PERRY;

Witnesses:

IIARRY L. DERBY, CHAs. Bmsnn, Jr. 

